With part of Marvel Phase Three and all of Marvel Phase Four unannounced, aside from a slew of mysterious release dates that span until 2019, many fans are wondering which projects will be slotted into the Marvel Cinematic Universe. One of the few projects that hasn't made it out of the development stage yet is Black Panther, which we reported last month is wanted by the fans more than Iron Man 4.

During an appearance at Fan Expo Canada over the weekend, Marvel legend Stan Lee confirmed that Marvel is still working on a Black Panther movie, while also hinting that the studio is working on a stand-alone movie for Scarlett Johansson's character Black Widow.

"We haven't made a Black Widow movie but she's been in some of our movies, and she will be featured more prominently as we move forward. And the chances are she will have her own movie because eventually all the superheroes are going to have their own movies. They are already working on Ant-Man, Doctor Strange and the Black Panther and there are others I am not allowed to talk about."

Production has already started on Ant-Man, but it isn't clear when Doctor Strange will start shooting, with Captain America 3 likely to follow that project, since it already has a May 6, 2016 release date scheduled. It isn't known when Doctor Strange will begin filming under the direction of Scott Derrickson. We reported earlier today that Joaquin Phoenix is still in talks to portray the title character, although he is hesitant about whether or not he should take on the role.

As for Black Panther, the Marvel character has been rumored to have an appearance in Avengers: Age of Ultron, since scenes were shot in South Africa, which may have been doubling for the character's fictional home country Wakanda.

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Actors such as Djimon Hounsou, Chadwick Boseman and John Boyega have expressed their interest in playing Black Panther in the past, but it seems Marvel isn't quite ready for casting at this time.

There are currently six open release dates that Marvel has mapped out up until 2019, three of which will most likely be reserved for Doctor Strange, Thor 3, The Avengers 3. It was also rumored last month that the studio is developing The Inhumans, but even if The Inhumans is happening, that leaves two unclaimed dates, one of which could easily be used for Black Panther.